gistfile1.php

<?php
// using Fieldmanager for a slideshow - any number of slides, with any number of related links
add_action( 'init', function() {
  $fm = new Fieldmanager_Group( array(
		'name' => 'slideshow',
		'limit' => 0,
		'label' => 'New Slide',
		'label_macro' => array( 'Slide: %s', 'title' ),
		'add_more_label' => 'Add another slide',
		'collapsed' => True,
		'children' => array(
			'title' => new Fieldmanager_Textfield( 'Slide Title' ),
			'slide' => new Fieldmanager_Media( 'Slide' ),
			'description' => new Fieldmanager_RichTextarea( 'Description' ),
			'posts' => new Fieldmanager_Autocomplete( 'Related Posts', array(
				'limit' => 0,
				'one_label_per_item' => False,
				'add_more_label' => 'Add another related link',
				'datasource' => new Fieldmanager_Datasource_Post( array(
					'query_args' => array(
						'post_status' => 'any',
					),
				) ),
			) ),
		),
	) );
	$fm->add_meta_box( 'Slides', array( 'post' ) );
} );